There’s a saying, “the customer is always right,” which may be true from a customer service standpoint, but that’s not the whole truth. As a vendor, it is your duty to be the expert in that. You gotta know how to best use it, how it fits your use case, and etc.
Maybe once upon a time, your sole job was selling, but those days are over. Nowadays, sales is much more consultative, and the expectation is that you, as the seller, will help buyers discover the right solution for their needs.
To be successful in business, you need satisfied customers who say good things about you. Tricking buyers into a sale was a pretty crappy model, and it’s completely unsustainable. The name of the game is helping buyers.